A Backward Month
April 2012 Summary

Dr. David A. RobinsonNew Jersey State ClimatologistCenter for Environmental Prediction, School of Environmental and Biological
Sciences/NJAES, Rutgers UniversityMay 3, 2012

While New Jersey experienced its 15th consecutive month of above-average temperatures, many residents of the state may think that April broke the string. What they may not recall is the 90° afternoon on the 16th or reaching the low 80°s at some locations as late in the month as the 21st. Rather, they remember the cool last week and a half of the month, the longest interval with below-average temperatures across the Garden State since an eleven day stretch late last October through the first week of November. That stretch included the first freeze of the season over much of the state on the 28th and the record breaking snowstorm on the 29th. The cool end-of-April period saw freezing temperatures in a number of locations occurring about two weeks after the average last freeze of the season. Jersey residents may also think that April had close-to-average precipitation, remembering the late season nor'easter that soaked the state on the 22nd. However there was very little additional precipitation, thus April was the 4th consecutive month with a below-average total.

The average temperature this past month of 52.6° is 1.4° above the 1981-2010 average. It was the 23rd warmest April since 1895. Being that this April was a bit cooler than April 2011, the twelve-month period ending this past March will remain as the warmest twelve-month period on record in NJ (out of 1397 such intervals since 1895). However, the twelve months ending this April is only 0.1° cooler and ranks as the second warmest on record.

The first four months of 2012 in NJ averaged 44.1°, which is 4.8° above average and the warmest start of any year on record (Table 1). When considering March 1 as the start of the growing season, which it certainly was this year, the March-April 2012 period was the 3rd warmest start to the season on record (Table 2). This resulted in the early blooming of vegetation in March, a trend that continued throughout April.

Rank

Year

Jan.-Apr. Avg. Temp.

1

2012

44.1°

2

1998

43.8°

3

2002

43.5°

4

1990

42.9°

5

1921

42.6°

6

1949

42.2°

6

2006

42.2°

8

1953

41.5°

8

1991

41.5°

10

2008

41.3°

Table 1. The ten warmest January-April intervals across New Jersey since 1895.

Rank

Year

Mar.-Apr. Avg. Temp.

1

1921

52.2°

2

1945

51.8°

3

2012

51.2°

4

2010

50.9°

5

1977

49.2°

6

2002

49.0°

7

1946

48.7°

7

1903

48.7°

9

1976

48.6°

10

1973

48.5°

10

1910

48.5°

Table 2. The eleven warmest March-April intervals across New Jersey since 1895.

There were four very warm April days where the thermometer topped 80° in many locations. Only coastal locations stayed failed to top 80° on at least one afternoon. The 15th saw Sicklerville (Camden County) reach 84° and the Burlington County towns of Mansfield and Eastampton get to 83°. The 16th was an exceptionally hot day for April. Seven stations spread out among five counties topped out at 91° and four at 90° (out of 50 stations in our NJWxNet that report daily highs and lows). The cool spots were West Cape May (Cape May) and Harvey Cedars (Ocean), both only reaching 69°. The warm spell continued on the 17th with Woodbine (Cape May) up to 83°, three stations at 82°, and ten reaching 81°. Hillsborough (Somerset) and Clayton (Gloucester) topped out at 83° on the 21st, just before the month-ending cool spell arrived.

Minimum temperatures fell to or below the 32° mark at one or more NJ stations on eighteen April mornings. Seven of those days saw a location drop to 25° or lower, starting on the 3rd when the northwest Jersey valley locations of Walpack (Sussex) and Pequest (Warren) fell to 23° to 24°, respectively. They repeated these marks on the 6th. Walpack dropped to 22° on the 7th and 8th, with Pequest checking in with 26° and 24°, respectively. These two stations reached 25° on the 13th. Berkeley Township (Ocean) and Walpack fell to 24° on the 28th, when 30 other stations were between 25° and 32°. On this coldest morning of the month, Atlantic City Marina (Atlantic) was the mild spot at 41°. Some locations fell to their monthly low on the 30th, although the 28th was colder statewide. Still, there were 22 stations reporting freezing temperatures, falling to as low as 25° at Berkeley Township. Harvey Cedars only dropped to 47°. Fortunately, the cold did not result in major damage to vegetation.

April was the 4th consecutive month with below-average precipitation across the Garden State. An average of 2.98" fell, which is 1.08" below normal and is the 42nd driest of the past 118 Aprils. Precipitation for January through April totaled 9.09" and was 5.52" below average and the 4th driest start of the year on record (Table 3). The first two months of the growing season rank as 14th driest with 4.93" having fallen. As a result of the persistent dry pattern, all parts of the state were in the D0 category (abnormal dryness) of the weekly National Drought Monitor map at the start of month. On April 12 the state moved to D1, which signifies moderate drought (yes, it is odd that there isn't a "minor" drought category).

Rank

Year

Jan.-Apr. Prcp

1

1985

6.80"

2

1946

8.83"

3

1927

9.06"

4

2012

9.09"

5

1992

9.10"

6

1995

9.29"

7

1963

10.08"

8

2009

10.41"

9

1930

10.45"

9

1981

10.45"

Table 3. The ten driest Januarys-Aprils across New Jersey since 1895.

The wettest location in April was Eatontown (Monmouth) with 4.04". Ocean Township (Monmouth) was next highest at 3.79", with Long Branch (Monmouth) and Mine Hill Township (Morris) both receiving 3.64". Bernards Township (Somerset) had the lowest monthly total at 2.08", followed by Pennsville (Salem) with 2.13", Pittman (Gloucester) at 2.21", and Burlington (Burlington) with 2.22".

There were only four rainfall episodes during the month, and only one of these was noteworthy. The 1st -2nd saw as much as 0.58" fall in East Greenwich (Gloucester) and 0.57" at Palisades Park (Bergen). Most of the state received 0.20"-0.40". Hardly any rain fell from the 3rd-18th, with warm temperatures throughout most of the period. This resulted in a fire danger alert being issued by the state on the 3rd, which was followed by almost daily brush or forest fires through the entire dry spell. A fire near the Camden-Atlantic county border on the 6th burned about 375 acres. The largest fire began on the 9th and consumed 1000 acres in Burlington County. While the larger fires were in the Pinelands region, no area in the state was immune to fire.

The fire danger began to subside with some light showers on the 19th-20th. Some dense fog occurred in central areas on the morning of the 19th and a thunderstorm visited Hammonton (Atlantic) on the evening of the 20th. However, it wasn't until a statewide event began to soak NJ on the 21st that the fire danger was greatly reduced. The first part of the storm brought late-evening thunderstorms to central and north Jersey on the 21st. The height of this late-season nor'easter was from late morning on the 22nd through the evening, with rain tapering off early on the 23rd. When all was said and done, of the 209 CoCoRaHS reports, the most rain fell in Monmouth County where Eatontown received 3.58"and Ocean Township 3.48". Ten stations had from 3.06"-3.25", 99 from 2.50"-2.99", 93 from 2.00"-2.49" and 16 from 1.33"-1.94". The lowest total was in East Greenwich (Gloucester). The southwest and northwest corners received the least. Rivers rose to near bank full in several areas and the Griggstown Causeway (Somerset) was closed due to flooding.

A minor event on the 26th brought 0.29" to Greenwich Township (Cumberland) and two Bridgeton (Cumberland) locations 0.26" and 0.24". Less than 0.10" fell outside of the southwest corner of the state. A light snow and sleet shower fell at High Point on the morning of the 27th for the only frozen precipitation of the month. Finally another minor round of precipitation saw 0.29" fall in Estell Manor (Atlantic) on the 28th-29th, with 0.25" in Egg Harbor Township (Atlantic), Woodbine (Cape May), and Stone Harbor (Cape May). Very little fell outside of the southeast region of the state.

Wind gusts topped out at 40 mph or greater at one or more NJ locations on twelve April days. On nine of those days the High Point Monument (Sussex) station fell into this category. This began with a 46 mph gust on the 2nd. The 3rd brought a 45 mph gust to Wantage (Sussex). High Point Monument reached 46 mph on the 4th, 41 mph on the 6th, and 47 mph on the 7th, when Wantage reached 43 mph. The 8th saw the Monument at 49 mph, Stewartsville (Warren) up to 42 mph, and Wantage at 41 mph. The 9th was a very windy day across the state. High Point Monument peaked at 60 mph, Stewartsville 55 mph, and Seaside Heights (Ocean) 50 mph. Thirteen stations peaked between 40-49 mph. High Point reached 40 mph on the 17th, with Upper Deerfield (Cumberland) maxing out at 46 mph on the 21st and Wantage at 40 mph. Atlantic City Marina (Atlantic) reached 43 mph on the 22nd, with Seaside Heights and High Point right behind at 42 mph and 41 mph, respectively. Wantage took top honors on the 24th with a 41 mph gust, and High Point Monument at 52 mph and Wantage at 44 mph on the 27th finishing the 40+ mph gusts of April.

The lowest monthly barometric pressure was achieved on the 23rd when readings were quite low at 29.10"- 29.15". The month's maximum pressure was reached on the 30th with values between 30.35" and 30.40" at many locations.